It's not getting any smarter out there...

Many people missed or ignored the opening credits of the program, and in the atmosphere of growing tension and anxiety in the days leading up to World War II, took it to be a news broadcast. Contemporary newspapers reported that panic ensued, with people fleeing the area, and others thinking they could smell the poison gas or could see the flashes of the lightning in the distance.

Professor Richard J. Hand cites studies by unnamed historians who "calculate[d] that some six million heard the Columbia Broadcasting System broadcast; 1.7 million believed it to be true, and 1.2 million were 'genuinely frightened'". (Hand, 7) While Welles and company were heard by a comparatively small audience (in the same time period, rival station NBC's audience was an estimated 30 million), the uproar that followed was anything but minute: within a month, there were about 12,500 newspaper articles about the broadcast or its impact (Hand, 7), while Adolf Hitler cited the panic, as Hand writes, as "evidence of the decadence and corrupt condition of democracy." (Hand, 7)

Later studies suggested this "panic" was far less widespread than newspaper accounts suggested. However, it remains clear that many people were caught up, to one degree or another, in the confusion that followed.

Robert Bartholomew and Hilary Evans suggest in Panic Attacks that hundreds of thousands of people were frightened in some way, but note that evidence of people taking action based on this fear is "scant" and "anecdotal." Indeed, contemporary news articles indicate that police were swamped with hundreds of calls in numerous locations, but stories of people doing anything more than calling up the authorities typically involve groups of ones or tens and were often reported by people who were panicking, themselves.

Later studies also indicated that many listeners missed the repeated notices that the broadcast was entirely fictional, partly because the Mercury Theatre (an unsponsored "cultural" program with a relatively small audience) ran opposite the popular Chase and Sanborn Hour over the Red Network of NBC, hosted by Don Ameche and featuring comic ventriloquist Edgar Bergen and singer Nelson Eddy, at the time three of the most popular figures in broadcasting. About 15 minutes into the Chase and Sanborn program the first comic sketch ended and a musical number began, and many listeners presumably began tuning around the dial at that point. According to the American Experience program "The Battle Over Citizen Kane", Welles knew the schedule of the Chase & Sanborn show, and scheduled the first report from Grover's Mill at the 12 minute mark to heighten the audience's confusion. As a result, some listeners happened upon the CBS broadcast at the exact point the Martians emerge from their spacecraft.

Many of these listeners were apparently confused. In fairness, it must be noted that the confusion cannot be credited entirely to naïveté. Though many of the actors' voices should have been recognisable from appearances on other radio shows, nothing like The War of the Worlds broadcast had ever been attempted in the United States, so listeners were accustomed to accepting newsflashes as reliable.

While there were repeated statements concerning the fictional nature of the program, no such statement was broadcast between the 12 minute and 40 minute marks. In fact, the warning at the 40 minute mark is the only one that occurs after the actors start speaking in character, and before Welles breaks character at the end. This structure is roughly similar to earlier Mercury Theatre broadcasts: due to the lack of sponsorship (which often included a commercial message at the 30-minute mark during an hour-long show), Welles and company were able to schedule breaks more or less at will, depending on the pacing of a given narrative.

While the War of the Worlds broadcast was in progress, some residents in northeastern cities went outside to ask neighbours what was happening (many homes still did not have telephones at this time). As the story was repeated by word of mouth, rumours began to spread, and these rumours caused some panic.

Contemporary accounts spawned urban legends, many of which persist and have come to be accepted through repetition as fact: Several people reportedly rushed to the "scene" of the events in New Jersey to see if they could catch a glimpse of the unfolding events, including a few astronomers from Princeton University who went looking for the "meteorite" that had supposedly fallen near their school. Some people, who had brought firearms, reportedly mistook a farmer's water tower for an alien spaceship and shot at it.